1. Field of the Invention
The present invention relates to a shift control system of a hybrid vehicle with an automatic transmission and a method thereof, and more particularly, to a shift control system of a hybrid vehicle with an automatic transmission that can improve acceleration feeling of the engine by driving the engine in advance before accelerating in accordance with the driver, and prevent decrease of fuel efficiency that may be caused by always driving the engine to improve the acceleration feeling, and a control method of the system.
2. Description of Related Art
In general, hybrid vehicle with an automatic transmission should perform kick down shift while driving the motor in order to perform the kick down shift in the EV (Electric Vehicle) mode in which the vehicle is driven by motors.
Since the motor has a feature that the torque decreases with the increase of the number of revolution, when the input number of revolution is increased by shifting to high stage for kick down shift, the motor torque decreases and the acceleration feeling is reduced.
In order to prevent this problem, it is possible to achieve acceleration feeling by starting the engine and engaging the engine clutch, after preventing kick down shift to implement the kick down shift through the engine. However, the vehicle is not accelerated while the engine starts and the engine clutch is engaged for the kick down shift, such that the driver does not satisfy the acceleration feeling.
Further, if the engine is continuously operated to prevent the unsatisfactory in acceleration, the fuel is wasted by continuous operation of the engine and the advantage of the fuel efficiency of the hybrid vehicles may be deteriorated.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.